Kilauea volcano in Hawaii sends lava into air as new vent opens

A new vent has opened at Kilauea, one of the world's most active volcanoes, sending lava shooting up to 20 metres into the air.

The fissure eruption was spotted shortly after the floor at the Pu'u O'o crater collapsed around 5pm local time on Saturday, the Hawaiian Volcano Observatory said.

It ran along the middle of Kilauea's east rift zone, about two miles west of Pu'u O'o.

"As a volcanogist, this is what we do. These are the moments we wait for," volcanogist Janet Babb told Hawaiian television station KHON2. "It is exciting to see an eruption begin, particularly if you can see it from the very start."

Scientists said areas near the vent at Kilauea, which has been in constant eruption since 1983, could erupt or collapse without warning, posing a threat to hikers.

In addition, potentially lethal concentrations of sulphur dioxide could be present up to half a mile downwind of vent areas.

Babb told the Hawaii Tribune-Herald that the fissure had expanded and is now almost a third of a mile long. He added that scientists were moving into the remote area to observe the fissure and take readings.

Following the latest activity, the Hawaii Volcanoes National Park has closed a number of roads and trails. Kulanaokuaiki campground was also closed until further notice. No homes are under threat.